Fuse-case.



T. E. MURRAY. FUSE CASE.

. APPLICATION FILED OCT. 17, 1910.

991,005. Patented May 2,1911.

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THOMAS E. MURRAY, OF NEW YORK, N. Y.

FUSE-CASE.

Specification of Letters Patent.

Patented May 2, 1911..

Application filed October 17, 1910. Serial No. 587,365.

To all whom it may concern:

Be it known that I, THOMAS E. MURRAY, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented a certain new and useful Improvement in Fuse-Cases, ofwhich the following is a specification.

Y The invention is a'fuse case, and consists in the constructionthereof, whereby the use of bolts or other separate fastenings and ofcemented joints between the parts to be united is obviated, while at thesame time the whole device is simplified and made exceedingly strong soas to be capable of withstanding the shock of a blowing fuse conveyingcurrents sufliciently great to shatter ordinary fuse cases. The fusecase body is a tube of or reinforced with, strong metal, such as iron orsteel, which is united and locked to its end holders, which arepreferably of porcelain, by simple bending of its own material, and themetal'contacts electrically connected to the fuse strip are also in likemanner joined to said holders.

In the accompanying drawings lligure 1 is a perspective view of myimproved fuse case. Fig. 2 is a longitudinal section on the line as, wof Fig. 3. Fig. 3 is a transverse section on the line 1 y of Fig. 2, andFig. 4. is a perspective view of the tubular fuse case body detachedfrom the end holders.

Similar letters of reference indicate like parts.

The fuse c'ase body A. is to be made of metal, preferably iron or steel,in tubular form, and, as shown in Fig. 3, is provided at each end withtwo flat and parallel projections B, C and D, E. The holdersF, G arealike, and are made preferably of porcelain or other refractoryinsulating material. Each end holder is flanged, as shown at H, and isprovided with two parallel slots to receive the projections B, C and D,E. The inner ends of the slots are preferably shouldered at I to formabutments for similar countersunk shoulders J formed at the junction ofthe projections B, C, l), E with the case body A. At the outer ends ofthe slots are countersunk shoulders, against which shoulders the flangedover extremities K of the projections B, O and D, E bear. In this waythe case A is firmly locked in the holders by bending its own materialand without the use of bolts or other separate fastening devices, or ofcemented joints. Centrally disposed in each holder is a longitudinalslot, through which slots pass the fuse strip L, which extends throughthe case body A. The slot is preferably somewhat larger in crosssectional area than the fuse stri and may be filled with plaster or likematerial, as shown at M. On the outside of each holder is a metalcontact plate which is bent to cover the bottom and two sides of theholder, as shown at N, O, P, and abuts against the flange H. Said plateis secured in place by integral bent over lugs Q which rest upon theupper surface of the holder. Another portion R of the contact plateextends upwardly from the bottom and lies against the outer face of theholder. In the portions R of the contact plates are formed slots toreceive the extremities of the fuse strip, so

that said fuse strip is thus electrically connected to said contactplates.

In assembling the device, the projections, as B, C, at one end of thecase body are inserted and secured in the holder as described, and theexterior metal contact plate is applied and the fuse strip is inserted.The space in the slot' in the holder which is not occupied by the fusestrip is then filled with wet plaster which is permitted to harden, andthe contact plate being applied, the extremity of the fuse strip iselectrically connected thereto. The body of the fuse case is filled withany suitable comminuted refractory insulating material, as shown at S,and, finally, the other holder is applied in the manner alreadydescribed. The resulting structure is solid and compact, free from boltsor like fastening devices, or from parts joined by cement, and hencehaving no parts to work loose orbecome separated. It

"is especially designed for fuses conveying heavy currents, and towithstand the shock incident to the blowing of such fuses. The flanges Hform barriers between the metal body of the fuse case and the metalcontact plates of the holders so as to prevent any possibility of aspark passing between them. It is preferable to provide the case bodyinside and out with a paper sheathing, T, U, to protect the metal fromoxidation, and as a guard to prevent contact of the operators hand withthe metal. The metal must be strong enough to resist the shock, but itsrelative thickness to the sheathing is immaterial. so that the tube maybe correctly described as either a metal tube sheathed with paper, or asa paper tube reinforced with metal. In using the device, the holders areinserted in the usual spring slips connected to circuit terminals, sothat circuit is completed through the fuse by way of the metal coveringplates, which, as is obvious, are completely insulated from the fusecase body by the solid refractory material of the holders.

1 claim:

1. The combination of a tubular case body of metal, holders ofrefractory insulating material, means for securing said case body at itsends in said holders, a fuse strip in said case body, and contacts onsaid holders electrically connected to said strip.

2. The combination of a tubular case body of metal, holders ofrefractory insulating material having openings receiving the ends ofsaid case body, in which openings said case body is secured by bendingthe material thereof, a fuse strip in said case body and said holders,and contacts on said holders electrically connected to said strip.

3. The combination with an inclosed fuse strip, of a tubular case bodyof flexible metal, holders of refractory insulating material havingopenings receiving the ends of said case body, and flexible metalcontact plates on said holders electrically connected to said strip; thesaid case body and the said plates being secured to said holders bybending the metal into suitable engagement therewith.

4. The combination of a tubular case body of metal having integrallyformed projections at its extremities, holders of refractory insulatingmaterial, means for securing said projections .in said'holders, a fusestrip in said case body and said holders, and contacts on said holderselectrically connected to said strip.

5. The combination of a tubular case body of metal having integrallyformed projee tions at its extremities, holders of refractory insulatingmaterial having slots receiving said projections and provided withcountersunk shoulders at their ends, over which the extremities of saidprojections are flanged, a fuse strip passing through said case body andsaid holders, and contacts on said holders electrically connected tosaid strip.

6. The combination of a tubular case body of metal having integrallyformed projections at its extremities, the said projections being bentto form shoulders at their junctions with said case body, holders ofrefractory insulating material having slots receiving said projections,each slot having a countersunk shoulder at its ends, the inner shouldersforming abutments for the said first-named shoulders and the outershoulders receiving flanged over extremities of said projections, a fusestrip in said case body and holders, and contact plates on said holderselectrically connected to said stri 7 The combination of a tubular casebody of metal, holders of refractory insulating material, means forsecuring said case body at its ends in said holders, a fuse stripextending through said case body and holders, and a contact platecovering two sides and the bottom of each holder and having a portionextending over the end face of said holder, the said last-named portionbeing electrically connected to an extremity of said fuse.

8. The combination of a tubular case body of metal, holders ofrefractory insulating material, each having a flange at one end, meansfor securing said case body at its ends in said holders, a fuse strip insaid case body and holders, and contact plates on said holders andelectrically connected to said strip; the flanges on said holders beingdisposed between said case body and said contact plates. 7

9. The combination of a tubular case body of metal, holders ofrefractory insulating material, means for securing said case body at itsends in said holders, a fuse strip and a filling of comminutedrefractory insulating material .in said case body, and contacts on saidholders connected to said strip.

10. The combination of a tubular case body of metal holders ofrefractory insulating material, internal and external sheathings offibrous material on said case body, means for securing said case body atits ends in said holders, a fuse strip and a filling of comminutedrefractory insulating material in said case body, and contacts on saidholders connected to said strip.

11. A. fuse case having an inclosing case of non-conducting fibrousmaterial reinforced with metal.

12. A. fuse case having a tubular case of metal with inner and outersheathings of non-conducting fibrous material.

13. The combination of a tubular case body of metal, a fuse striptherein, holders of refractory insulating material, means for securingsaid case body in said holders, contact plates on said holderselectrically connected to said fuse strip, and barriers of insulatingmaterial interposed between said case body and said contact plates.

14. The combination of a tubularcase body of metal, a fuse striptherein, holders eennoos g;

of refractory insulating material, means for In testimony whereof I haveaflixed my SGCHI'iIIIg said case bgldyl din saild holdefi's,consignature in presence of two witnesses. tact p ates on said 0 ers eectrica y connected to said fuse strip, and barriers of in- THOMASMURRAY 5 sulating material formed integrally on said Witnesses:

holders and interposed between said case GERTRUDE T. PORTER, body andsaid contact plates. MAY '1. MCGARRY.

